Another Low-RPM Moment in an R-44

[r22butters]

 

I put this in the Training Forum because it seems to be happening more often these days?

[adam32]

Dang...looks like he had plenty of time to recover unless it was a mechanical failure.

 

I don't think it's happening more, just more gopros around recording everything!

[Pohi]

That's no good.

 

Looks like the rotor was down to maybe 60% at the end 0:35 or so into the video.

 

Hope they walked away.

[ARM_Coder]

Another crash in Brazil... in a city called Canela, RS state.

 

Somehow he lost power, and somehow he thought he would make it to the airport. Indeed he crashed inside the airport lot.

 

Why he didn't opt to land / autorotate with so many available areas is beyond me.

 

Crash site: https://www.google.com.br/maps/place/29%C2%B021'56.4%22S+50%C2%B049'39.4%22W/@-29.3656607,-50.8287082,332m/data=!3m2!1e3!4b1!4m5!3m4!1s0x0:0x0!8m2!3d-29.365663!4d-50.827611?hl=pt-BR

 

Edit: no one died in the crash, the aircraft had 3 POB from which two ended slightly injured.

[r22butters]

That's no good.

Looks like the rotor was down to maybe 60% at the end 0:35 or so into the video.

Yeah saw that with the MAP way up! I've been under the impression that at 80% the rotor stalls and you drop out of the sky like a brick, but this doesn't look that extreme (but more like a 22 in normal autorotation) until the very end where he shutters right before the crash?

 

Would love to hear the experts opinion!

[Pohi]

In my early days as a CFI, before I was experienced enough to predict the absolutely retarded things that are likely to happen, I saw less than 80% rotor RPM when a student did about 3 of the absolute worst things for rotor RPM in the span of a second and a half.

 

There were all kinds of noises and shaking in the helicopter, but most were probably due to the seat being torn from its frame and being sucked up into my keister.

 

They put safety margins in that kind of stuff, so at 79% the blades aren't going to stall and fold up.

[r22butters]

They put safety margins in that kind of stuff, so at 79% the blades aren't going to stall and fold up.

So the "real" stall number is in the "secret" POH?

[Wally]

In my early days as a CFI, before I was experienced enough to predict the absolutely retarded things that are likely to happen, I saw less than 80% rotor RPM when a student did about 3 of the absolute worst things for rotor RPM in the span of a second and a half.

 

There were all kinds of noises and shaking in the helicopter, but most were probably due to the seat being torn from its frame and being sucked up into my keister.

 

They put safety margins in that kind of stuff, so at 79% the blades aren't going to stall and fold up.

 

Never ever rely on unpublished margins in performance or structure. They may or may not exist, they may of may not cause an immediate catastrophic failure, they may or may not cause cumulative damage that will eventually render the air frame unsafe in normal operation. If you experience the situation and survive, the hammer on your Russian roulette pistol just clicked on an empty cylinder. If and when you survive and land, write the event up clearly for maintenance review immediately.

Strict adherence to RFM limits won't make your flight safe, but it keeps you and all successive PICs from inadvertently becoming test pilots in a failing air frame.

 

P.S. Every student you teach is determined to kill you with stupid flying/planning. The really, really dangerous students are the ones you think are 'good'.

Edited February 28, 2017 by Wally

[rockapotomus]

 

 

P.S. Every student you teach is determined to kill you with stupid flying/planning. The really, really dangerous students are the ones you think are 'good'.

 

As someone currently going through CFII training, I'm throwing this wisdom in my back pocket.